FW Downgrade error when no BIOS update attempted?

[Hugh Jay]

I have a 3rd-gen Lenovo Thinkpad X1 Carbon running Ubuntu 22.04. It has stock UEFI/BIOS version N14ET25W (1.03) from 2014-12-01 and ME Firmware Version 10.0.29.1000.  I've had it for many years without issue.

But this year, on two separate dates, I've had errors when powering on: "Me FW Downgrade - Request MeSpiLock Failed". Both times it eventually resolved after a few reboots.

My research shows this error is normally associated with a failed UEFI/BIOS firmware update. But I have never made any attempt to update my firmware on this device.

Ubuntu has a service called "fwupd" that can try to keep your firmware up-to-date. But when I run this command, it shows no attempts to update my firmware by fwupd:

Code:

$ fwupdmgr get-history
WARNING: UEFI capsule updates not available or enabled in firmware setup
See  for more information.
No history

Can anyone suggest a plausible explanation for why this "Me FW Downgrade - Request MeSpiLock Failed" error ocurred - seemingly without any cause?